OK, got 'em back:

https://telnet25.wordpress.com/2014/09/29/arbitration-mailbox-exchange-2010-and-2013/

Thanks,
Jeff Bowman
Fairbanks, Alaska

• Edited by Jeff.Bowman 7 hours 45 minutes ago

New at this, so may be asking the wrong questions. Please advise accordingly.

I've just finished installing Exchange 2013 into my small Server Essentials 2012 R2 domain (I put it on a separate VM from the DC). I worked on it all day yesterday.

Much to my chagrin, I received a Health Report warning this morning that I'd exceeded my 25-account allotment in WSE. Needless to say, this surprised meI'd only created 10 so far. There should've been plenty of room.

Well, it seems that Exchange Setup had gone and added its own18 of them, to be exact. Here's what I've got:

Do I really need all of these? What are they used for? How quickly would Exchange go belly-up if I just deleted them all?

I have to do something... I don't know whether the DC's going to shut me down over this, but I'd hate to consider it.

Thanks,
Jeff Bowman
Fairbanks, Alaska

I wouldn't think that those mailboxes would be counted against your WSE licenses, but I'm not authorized to quote licensing terms on behalf of Microsoft.

I wouldn't think that those mailboxes would be counted against your WSE licenses

Now you know ;-)

FYI I've just found a good lead:

'Small Business Susan'

Here's what I've been up to in the time since my original post:

Server Fault

I found Susan's post AFTER I'd disabled the -Arbitration mailboxes and removed the accounts. I've probably gummed things up by doing soI hope not.

Thanks,
Jeff Bowman
Fairbanks, Alaska

Well, one arbitration mailbox contains the offline address book, so you've certainly broken that if you deleted that particular mailbox.

That's the one I left standing, for that precise reason.

How about the others? Essential they were?

Thanks,
Jeff Bowman
Fairbanks, Alaska